Would like a girl but what is the best time?

my partner and I have a son and would like to try and concieve a girl. My dob is 13th April 1976. What is my lunar age and when would be the best time to concieve a girl after may this year. Also we would like to get married before I am 40. My partners dob is 30th October 1973. Shay year/month would be the best for us to have the best start to our marriage.